Why does nobody talk about how magnetic stud finders are useless on lath and plaster?

After my $30 stud finder kept beeping at nothing for an hour, the old guy at Sunrise Hardware told me to just use a strong fridge magnet and tap for hollow spots, and it found every stud in my 1942 Nob Hill living room on the first try.

2 comments

2 Comments

wilson.claire5d ago

Just use a strong fridge magnet and tap for hollow spots" - okay but seriously, did the old timer explain WHY that works better than the electronic ones? Is it just a lath and plaster thing, or are those stud finders basically useless on all old walls?

terry_walker5d ago

Oh man, that’s exactly what I’ve run into with my 1920s place. Those electronic stud finders just go crazy on lath and plaster, picking up all the metal mesh or keys underneath, a magnet is way more reliable for finding the nails in the studs.